The Kvichak River drains into Bristol Bay, which supports the largest sockeye salmon fishery in the world. Estimates of abundance of outmigrating smolts from the Kvichak River are used to help prepare preseason forecasts of adult returns and to set escapement goals.
The goal of this project was to develop a new system that can replace and improve upon an up-looking Bendix smolt counter, which had been used on the Kvichak River since 1975. To increase the cross-sectional area sampled we used a side-looking acoustic system. However, this system configuration required us to develop a new technique for echo integration that accounts for the non-uniform vertical distribution of smolts. We developed such a technique in collaboration with Robert Kieser and Tim Mulligan from the Department of Fisheries and Oceans, Canada. Video data collected by Nick Hughes (University of Alaska, Fairbanks) and Lee McKinley (Alaska Department of Fish and Game) provided information on the vertical distribution of smolts and were used as an independent dataset to validate the echo integration results.
References
Mueller, A. M., Degan, D. J., Kieser, R., and T. Mulligan. 2006. Estimating sockeye salmon smolt flux and abundance with side-looking sonar. North American Journal of Fisheries Management 26: 523 – 534, 2006.